Phytosynthesis of zinc oxide nanoparticles for enhanced antioxidant, antibacterial, and photocatalytic properties: A greener approach to environmental sustainability.

Multifunctional nanoparticles (NPs) production from phytochemicals is a sustainable process and an eco-friendly method, and this technique has a variety of uses. To accomplish this, we developed zinc oxide nanoparticles (ZnONPs) using the medicinal plant Tinospora cordifolia (TC). Instruments such as UV-Vis, XRD, FTIR, FE-SEM with EDX, and high-resolution TEM were applied to characterize the biosynthesized TC-ZnONPs. According to the UV-vis spectra, the synthesized TC-ZnONPs absorb at a wavelength centered at 374 nm, which corresponds to a 3.2 eV band gap. HRTEM was used to observe the morphology of the particle surface and the actual size of the nanostructures. TC-ZnONPs mostly exhibit the shapes of rectangles and triangles with a median size of 21 nm. The XRD data of the synthesized ZnONPs exhibited a number of peaks in the 2θ range, implying their crystalline nature. TC-ZnONPs proved remarkable free radical scavenging capacity on DPPH (2,2-Diphenyl-1-picrylhydrazyl), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid), and NO (Nitric Oxide). TC-ZnONPs exhibited dynamic anti-bacterial activity through the formation of inhibition zones against Pseudomonas aeruginosa (18 ± 1.5 mm), Escherichia coli (18 ± 1.0 mm), Bacillus cereus (19 ± 0.5 mm), and Staphylococcus aureus (13 ± 1.1 mm). Additionally, when exposed to sunlight, TC-ZnONPs show excellent photocatalytic ability towards the degradation of methylene blue (MB) dye. These findings suggest that TC-ZnONPs are potential antioxidant, antibacterial, and photocatalytic agents.

Seaweed Sargassum wightii mediated preparation of zirconia (ZrO2) nanoparticles and their antibacterial activity against gram positive and gram negative bacteria.

In the present study, a facile and green combustion method has been optimized for the synthesis of zirconia (ZrO2) nanoparticles using marine brown alga (seaweed), Sargassum wightii (S. wightii). Structural, optical and photoluminescence properties of the prepared ZrO2 nanoparticles were studied using XRD, FTIR, HR-TEM, UV-vis and PL spectroscopy. The average grain size of the nanoparticles calculated from the XRD pattern was around 4.8 nm which exhibits tetragonal structure. TEM results showed that the synthesized nanoparticles were uniformly monodispersed without aggregation. Formation of zirconia nanoparticles were confirmed by FTIR studies. The PL spectra exhibit broad emission peaks at the interface of UV and visible regions which can be assigned to the ionized oxygen vacancy in the material. Antibacterial activity of the synthesized zirconia nanoparticles was studied against gram positive and gram negative bacterial strains using agar well diffusion method. The prepared zirconia nanoparticles show significant antibacterial effect against Bacillus subtilis, Escherichia coli and Salmonella typhi due to their large surface area by their nanosize.

Genetic variability and potential recombination events in the HC-Pro gene of sugarcane streak mosaic virus.

Sugarcane streak mosaic virus (SCSMV), a member of the family Potyviridae, is an important viral pathogen affecting sugarcane production in India. The variability in the nucleotide (nt) and amino acid (aa) sequences of helper component proteinase (HC-Pro) of SCSMV isolates from India was investigated and compared with those of previously published virus isolates from different Asian countries. Comparison of all of the sequenced virus isolates revealed a high level of diversity in the HC-Pro gene (72-97% nt sequence identity; 83-99% aa sequence identity), and the Indian isolates were found to be the most divergent (up to 12% variation at the amino acid level). Phylogenetic analysis revealed clustering of 16 SCSMV isolates into two groups. Group I included isolates from India and Pakistan, and group II consisted of isolates from Japan and Indonesia. Recombination analysis revealed nine potentially significant recombination events, and putative recombination sites were identified throughout the HC-Pro gene. Analysis of selection pressure indicated that the HC-Pro gene of SCSMV is under strong negative selection. It is likely that recombination, along with strong negative selection, enhances the speed of elimination of deleterious mutations in the HC-Pro gene.

Utilization of induction furnace steel slag in concrete as coarse aggregate for gamma radiation shielding.

The present investigation highlights the utilization of Induction Furnace (IF) steel slag as a partial replacement for coarse aggregate in concrete. The concrete blocks of size 150 × 150 × 50 mm were casted and the effect of density, compressive strength, linear attenuation coefficient, Gamma Attenuation Factor (GAF) and Half Value Layer (HVL) has been explored. Gamma attenuation measurements were carried out using NaI (Tl) based gamma detector. Gamma ray source 60Co emitting two gamma energies 1.17 and 1.33 MeV was used for radiation measurements. The results of this present study shows that 50% of IF steel slag replacement increases the density (2.81 g/cm3) and compressive strength (29.11 N/mm2). The Linear attenuation coefficient (0.1953 cm-1-0.2236 cm-1) and GAF (0.6343-0.6710) is higher at 50% replacement of IF steel slag than conventional concrete. HVL values were also having positive impact in 50% replacement of IF steel slag (3.10 cm) in concrete than conventional concrete (3.55 cm). The partial replacement of IF steel slag as coarse aggregate in concrete is effective in gamma shielding.

A comparison between hot-hydrolysis and sonolysis of various Mn(II) salts.

A variety of manganese salts ranging from completely soluble and ionized to insoluble compounds have been subjected to ultrasonic radiation in aqueous medium at pH approximately 8.3. All of the manganese salts yielded a product identified as nanoparticles of Mn(3)O(4), expect for MnCO(3), which yields of mixture of phases. The characteristics of the products obtained are compared with those obtained under vigorous stirring conditions. The shapes of nanocrystals varied from sharp-edged crystals to smooth particles.

Functionalization of gold nanoparticles as antidiabetic nanomaterial.

In the present investigation, functionalization of gold nanoparticles synthesized using propanoic acid 2-(3-acetoxy-4,4,14-trimethylandrost-8-en-17-yl) (PAT) an active biocomponent isolated from Cassia auriculata is studied in detail. On reaction of PAT with aqueous HAuCl4, rapid formation of stable gold nanoparticles was achieved. Formation of gold nanoparticles was confirmed by UV-vis spectroscopy, XRD, GC-MS,FTIR, TEM and SEM with EDAX. Gold nanoparticles mostly were monodisperse, spherical in shape and ranged in size 12-41 nm. Gold nanoparticles synthesised using PAT was administered to alloxan (150 mg/kg body weight) induced diabetic male albino rats at different doses (0.25, 0.5, 0.75 and 1.0mg/kg body weight) for 28 days. Plasma glucose level, cholesterol and triglyceride were significantly (p<0.001) reduced in experimental animals treated with gold nanoparticles at dosage of 0.5mg/kg body weight and plasma insulin increased significantly. The newly genre green gold nanoparticles exhibit remarkable protein tyrosine phosphatase 1B inhibitory activity.

Biosynthesis of antibacterial gold nanoparticles using brown alga, Stoechospermum marginatum (kützing).

Biological synthesis of gold nanoparticles by brown alga, Stoechospermum marginatum biomasses through a green route was reported in this study. The formation of the gold nanoparticles was observed within 10 min. The properties of prepared nanoparticles were characterized by photoluminescence spectra, Fourier Transform Infrared Spectroscopy, scanning electron microscopy, Transmission Electron Microscopy, X-ray diffraction, particle size analysis and quantified by Wavelength Dispersive X-ray Fluorescence Spectrophotometer. The synthesized gold nanoparticles were found to be photoluminescent. The formation of gold nanoparticles was confirmed by the presence of an absorption peak at 550 nm using UV-visible spectrophotometer. TEM image revealed that most of the particles are spherical in shape and some are hexagonal and triangle with size ranged from 18.7 to 93.7 nm. The nanoparticles were crystalline in nature and it was confirmed by XRD pattern and the presence of elemental gold (45.92%) was confirmed by WD-XRF. From the FTIR measurements it is noticed that the reduction has been carried out by hydroxyl groups present in the diterpenoids of the brown seaweed. Furthermore the biologically synthesized gold nanoparticles were found to be effective against bacterial pathogens.

Sargassum myriocystum mediated biosynthesis of gold nanoparticles.

Functionalized metal nanoparticles are unique in nature and are being developed for its specificity in drug targeting. In the present study, aqueous extract of Sargassum myriocystum is used for the biosynthesis of gold nanoparticles (AuNPs) by the reduction of chloroauric acid. The formation of nanoparticles reaction was complete within 15 min at 76 °C. The size, shape and elemental analysis of AuNPs were carried out using UV-visible absorption spectroscopy, FT-IR, TEM, SEM-EDAX, and XRD analysis. The newly formed AuNPs are stable, well-defined, polydispersed (triangular and spherical) and crystalline with an average size of 15 nm. The biomolecule involved in stabilizing AuNPs was identified using GC-MS.